By now most people have heard of cars that run on vegetable oil. Used oil that drivers get for free from restaurants. But is it really free? And can the average person see savings and drive that kind of car everyday? The short answer is yes - with some elbow grease.

Justin Carven, Founder and Inventor of Greasecar says, "We have a lot of customers who have three Greasecars in the family."

And that family could be starting up the tiniest of cars or the biggest of pick-up trucks. All you need is a few extra parts, about $2000 dollars, and you're off and running.

Carven says, "You fill up your diesel tank, you fill up your vegetable oil tank and for a lot of folks it will last them several weeks."

That's right weeks and two tanks. Justin Carven is the founder and inventor of Greasecar in Easthampton. He's designed a system that fits into any diesel car that makes the motor run on either vegetable oil or diesel.

Carven says, "You always need to start it on diesel fuel and once the vegetable oil is heated up then you can switch it over and just run it on vegetable oil."

Then you can just press a button and it switches back to diesel. So, you won't get stuck in the middle of nowhere with no vegetable oil in sight. Now that brings us to the question of where do you get the vegetable oil.

Carven says, "Our customers, in general, are using waste cooking oils for their fuel. French fry oil from restaurants they get it for free. It's a heck of a lot cheaper than at the pump."

But there is a catch. And this is where it might not be for everyone. You can't put the used oil right into your tank. It's a waste product. So you need to get out the old food and the water that's in there from the restaurant. And that's a process.

Carven says, "You get the oil and let it settle for as long as possible - a few weeks in a container. The settling allows any water and small particles to settle out. Then it's generally heated up and run through a filter."

For many drivers throughout the country that's really their only option but because we live in the Pioneer Valley - home of Greasecar - drivers have another option in Easthampton and in Greenfield.

Carven says, "This is our version of a gas station."

And just like at the pump, this fuel is not free. Right now, it sells for $3.10 a gallon - that's because it's from a company that processes the oil itself and includes state and federal gas taxes. The price of vegatble oil also fluctuates like gas. But with diesel at about $4.70 a gallon, it's still cheaper.

Carven says, "Three and half gallons which is good for about almost 200 miles on this car."

The other price tag is the cost of the system. What car you own depends on how much the system costs - small car conversion kits are just under $1000 dollars and truck kits up to $3,000. But with fuel prices so high - you'll get that back almost as fast as you can fuel up a Mini. And people are taking notice.

Carven says, "We've been breaking some records this past month."